146,264 research outputs found
Using performance assessment in secondary school mathematics: an empirical study in a Singapore classroom
No full textThis article reports an exploratory study on using performance assessment in mathematics instruction in a high-performing secondary school in Singapore. An intact mathematics class participated in the study, and received chapter-based performance tasks as intervention during regular mathematics lessons for about one and a half school years. The performance tasks used included authentic and/or open-ended tasks. The students’ academic achievements and attitudes in mathematics were compared with a comparison class that did not receive the intervention. Both quantitative and qualitative data were collected, mainly through questionnaire surveys, performance task tests, conventional school exams, and interviews with students and teachers. The results suggest that the students receiving the intervention performed significantly better than their counterparts in solving conventional exam problems, and in general they also showed more positive changes in attitudes towards mathematics and mathematics learning. The students from the experimental class also expressed positive views about the benefits of using performance tasks in promoting their ability in higher order thinking, though no statistically significant difference was detected between the two classes of students in solving unconventional tasks before and after intervention. Overall, the results appear to support teachers’ using contextualised problems in real life situations and open-ended investigations in students’ learning of mathematic
Experimental study of blade thickness effects on the global and local performances of a Controlled Vortex Designed axial-flow fan
No full textThe purpose of this work is to study the effects of blade thickness on the performances of an axial-flow fan. Two fans that differ only in the thickness of their blades were studied. The first fan was designed to be part of the cooling system of an automotive vehicle power unit and has very thin blades. The second fan has much thicker blades compatible with the rotomoulding conception process. The global performances of the fans were measured in a test bench designed according to the ISO-5801 standard. The curve of aerodynamics characteristics (pressure head versus ow-rate) is slightly steeper for the fan with thick blades, and the nominal point is shifted towards lower flow-rates. The efficiency of the thick blades fan is lower than the efficiency of the fan with thin blades but remains high on a wider flow-rate range. The mean velocity field downstream of the rotors are very similar at nominal points with less centrifugation for the thick blades fan. The thick blades fan moreover maintains an axial exit-flow on a wider range of flow-rates. The main dierences concern local properties of the flow: Phase-averaged velocities and wall pressure fluctuations strongly differ at the nominal flow-rates. The total level of fluctuations is lower for the thick blades fan that for the thin blades fan and the spectral decomposition of the wall fluctuations and velocity signals reveal more harmonics for the thick blades fan, with less correlation between the different signals. For this kind of turbomachinery, the use of thick blades could lead to a good compromise between aerodynamic and acoustic performances, on a wider operating range
fan v
No full textfan v_OED_ ~ v 2 'of the wind: to blow' now fare (_1671, 1699_, 1889)naut citesNot usedNot usedQuerie
Experimental study of blade rigidity effects on the global and the local performances of a thick blades axial-flow fan
No full textAn experimental investigation on the aerodynamic performances of thick blades axial-flow fans was carried out in this study. Two fans are considered, the first one is rotomoulded (in plastic) and the second one is milled (in aluminium). Both have exactly the same shape, excepting that the rotomoulded fan has hollow blades. They were designed from an existing fan (manufactured by plastic injection process) used in the cooling system of an automotive vehicle power unit. As far as shape is concerned, the only difference between the two first fans and the traditional injected fan is the blade thickness, whereas as far as rigidity is concerned, the only difference between the rotomoulded and the milled fans is the ability of the rotomoulded fan to be deformed easier than the milled fan. The aim of this study is to determine on the one hand the influence of the blade thickness and on the other hand the way the deformation of the hollow blades may affect the global and the local performances. The global performances of the fans were measured in a test bench designed according to the ISO 5801 standards. The curve of the aerodynamics characteristics (pressure head versus flow rate) and of the global efficiency are slightly lower for the rotomoulded fan. The wall pressure fluctuations were also investigated for three flow rates: one corresponding to the maximum efficiencies of both fans and two others corresponding to an under-flow and an over-flow rate. The power spectral density (PSD) levels, estimated by the Welch method, are between six and nine times higher for the rotomoulded fan at nominal flow rate. At partial flow rate, however, the PSD levels are close for both fans
Analysing International Sports Fan Motivations and Constraints: The Case of Japanese International Sports Fan Tourists and Rugby World Cup Fan Tourists
No full textThe scale of professional sports leagues and mega sports events has expanded recently. Many sports fans travel to foreign countries to watch international events featuring the world’s top athletes or players. The number of international sports fan tourists has increased, and understanding their behaviour is very important for stakeholders and those involved in marketing, such as sports organisations, travel companies, and government tourist organisations.
This study examines the motivations and constraints of Japanese international sports fan tourists and Japanese Rugby World Cup fan tourists. Sports fan tourists are tourists as well as sports fans. Many researchers have examined motivation either from a sports fan’s perspective or a tourist perspective. However, a motivation scale for international sports fan tourists (combining both sports fan and tourist motivations) has been not developed as there has been a lack of research into the behaviour of the international sports fan tourist.
The main research aim of this study is to analyse the motivation and constraint factors of both Japanese international sports fan tourists and Japanese Rugby World Cup tourists. The methodology aims to:
1.profile Japanese international sports fan tourists and Japanese Rugby World Cup tourists;
2.develop a motivational scale for actual sports fan tourists and a constraints scale for potential sports fan tourists (those who considered going but did not go);
3.analyse these factors according to demographics;
4.examine factors related to motivations and constraints on fans’ satisfaction, or their intention to attend future events.
A quantitative approach was employed. The main data collection methods were three email surveys:
1.Study 1 collected data about actual international sports fan tourists (N=338) and potential sports fan tourists (N=292).
2.Study 2 collected data about actual Rugby World Cup 1987-2007 tourists (N=101) and potential tourists (N=297).
3.Study 3 collected data about actual Rugby World Cup 2011 tourists (N=84) and potential tourists (N=115).
In previous studies, the sample was collected either from actual fans or potential fans separately; however, in this study, samples were collected not only from actual sports fan tourists but also from potential sports fan tourists from the same database.
The data analysis predominantly used explanatory factor analysis (EFA), confirmatory factor analysis (CFA), independent t-test, ANOVA, regression analysis, and structure equation modelling (SEM) including interaction effects analysis.
The results of this study were analysed using four steps:
1.Showing the demographic profiles and behavioural patterns of Japanese international sports fan tourists and Japanese Rugby World Cup fan tourists.
2.Developing motivation and constraints scales:
• an International Sports Fan Motivation Scale
• an International Sports Fan Tourist Motivation Scale
• an International Sports Fan Constraints Scale
• a Rugby World Cup Sports Fan Motivation Scale
• a Rugby World Cup Fan Tourist Motivation Scale
• a Rugby World Cup Fan Constraints Scale.
3.Comparing the mean scores of extracted factors by demographics such as gender, age, sports experiences etc.
4.Analysing the impact on satisfaction or future intention using interaction effect methods.
The results showed some interesting academic and practical implications. This study has thus made a significant and unique contribution to the knowledge of international sports fan behaviour by researching the combined sports fan motivation factors and tourist motivation factors of actual sports fans, and the constraints of potential sports fan tourists. The study has also provided an academic contribution to the sports and tourism fields, and has provided a practical contribution to the areas of sports fan behaviour, tourism, leisure constraints, and sports events management
Aerodynamics of lift fan V/STOL aircraft
No full textAerodynamic characteristics of lift fan installation for direct lift V/STOL aircraf
Fan V/STOL aircraft
No full textAerodynamic characteristics and test data of fan powered V/STOL aircraf
Da fan xian tian zou gao fu mi
No full text[V.1-2]. 卷上. 大梵先天奏告元科 -- [v.3-4]. 卷下. 大梵先天奏告符秘.[V.1-2]. Juan shang. Da fan xian tian zou gao yuan ke -- [v.3-4]. Juan xia. Da fan xian tian zou gao fu mi.[婁近垣撰].綫裝, 1函.框22.6x15.5公分, 9行15字, 小字雙行同. 白口, 單魚尾, 四周雙邊. 版心上鐫題名, 中鐫卷次, 下鐫葉次.題名據版心.分上, 下卷.前有婁近垣序.按: 是書《販書偶記》著錄為"康熙間綠硃墨三色印本". 此帙卷下為硃墨黄綠四色套印. 又"丘"避諱改"邱", "真"剜改缺筆, 當為雍正間印本.Xian zhuang, 1 han.Kuang 22.6 x 15.5 gong fen, 9 hang 15 zi, xiao zi shuang hang tong. Bai kou, dan yu wei, si zhou shuang bian. Ban xin shang juan ti ming, zhong juan juan ci, xia juan ye ci.Ti ming ju ban xin.Fen shang, xia juan.Qian you Lou Jinyuan xu.Detailed notes in vernacular field only.[Lou Jinyuan zhuan]
MEASUREMENT OF FAN CHARACTERISTICS
No full textkatedra: KEZ; přílohy: 2 CD ROM; rozsah: 37Purpose of this work is detection of dimensional radial ventilation fan. Radial ventilation fan is situated on the Technical University of Liberec in the laboratory. Ventilation fan was made in 1961. Due to this fact there is only small amount of source materials. The only I have, are in suplement II. The main research of this project was checking up parameters from the ventilator label up and finding it´s dimensionality. In the first chapter I present generally about the theory of ventilation fan. In the second chapter there is describted ventilator´s way. In items is mentioned control process in the third chapter. In the fouth chapter you can find measurement results. In the fifth chapter I write about observed characteristic of ventilator fan and matching both gauges. There is final result of measurement. In the last chapter I refer back laboratory measurement. Presentive results of particular measurements are in supplement I. In suplement III I show prefigurative calculation.Cílem této bakalářské práce je zjištění charakteristiky radiálního ventilátoru. Radiální ventilátor umístěný v laboratoři Technické univerzity v Liberci. Ventilátor byl vyroben v roce 1961 a veškeré podklady k ventilátoru již nejsou k dispozici. Pouze jen ty, které jsou v příloze II. Hlavním úkolem tedy bylo ověřit parametry na štítku na ventilátoru a zjistit jeho charakteristiku. V první kapitole uvádím obecnou teorii ventilátorů. V druhé kapitole je popsána v jednotlivých bodech ventilátorová trať. V třetí kapitole je uveden postup měření. V čtvrté kapitole jsou uvedeny výsledky měření. V kapitole páté jsou zjištěny charakteristiky ventilátoru, ale také porovnání dvou měřidel. V šesté kapitole je závěr celého měření. V poslední kapitole je návrh laboratorního měření. Konkrétní výsledky jednotlivých měření jsou v příloze I. V příloze III. je uveden vzorový výpočet
Countable fan-tightness versus countable tightness
No full textsummary:Countable tightness is compared to the stronger notion of countable fan-tight\-ness. In particular, we prove that countable tightness is equivalent to countable fan-tightness in countably compact regular spaces, and that countable fan-tightness is preserved by pseudo-open compact mappings. We also discuss the behaviour of countable tightness and of countable fan-tightness under the product operation
- …
